I'm currently trying to get Linux Mint 18.2 to work in Oracle Virtual Box.

What have I done so far:

Installed VBoxAdditions 5.0.40 or 5.1.26 (first one through apt-get, second one through the VirtualBox-Guest-Additions .iso itself). That does not mean that I installed them concurrently, after each try I removed the packages with following method:

I have to note that the whole system became extremly sluggish and unusable during that benchmark.

In general everthing seems to "work". The usual things associated with Guest-Additions (copy-and-paste, resizing the windows, etc.) seem to work. Browsing with firefox is extremly smooth, even smoother than browsing with Chrome on my Host machine.

But as soon as 3D-accelerated things have to be drawed (it seems like the cinnamon-menu is 3D-accelerated too), my CPU usage on the host machine rises from 0-10% to 40-80% and in general everything becomes extremly laggy. I'm just talking about TYPING single characters in the search bar on the cinnamon start menu. Whenever I type something in firefox or other entering masks, it's extremly smooth. But as soon as I do that in the menu or use other 3D-accelerated things, it seems like the drawing of the 2D-desktop slows down to 5-10 FPS.

I tried to not use the 3D-acceleration, namely using software-rendering. On a restart, the message that I am currently using software-renering and therefore the UI can seem sluggish appeared.

But quite the contrary. The menu is smoother (NOT smooth. But I would guess something around 15 FPS) and the benchmark (glxgears) showed something around 650 FPS, so about 3x of that we archieved before. So clearly there is something not working correctly with the hardware acceleration.

That's a pretty specific issue. If no one here can help, you might try the VirtualBox Forums. For example, I notice a recent thread there with a similar issue, which a mod diagnosed as hardware related. Hopefully your outcome will be different.

Sorry can't be more help. Only started with VBox a couple days ago.

Time flies like an arrow. Fruit flies like a banana.
Running Mint 18.3 Mate 64 bit (by upgrade from 18.1-2)